Nutritional rickets under 16 years: UK surveillance results.
Level 4 - case-series / case-control
Prospective national descriptive surveillance case series without an unexposed comparator group
PubMed 31949032 · doi:10.1136/archdischild-2019-317934
What was done
Prospective national active surveillance was conducted across the UK between March 2015 and March 2017 via the British Paediatric Surveillance Unit, covering monthly reports from 3500 consultant paediatricians. Clinicians completed online questionnaires for children under 16 years presenting to secondary care who met the surveillance case definition for nutritional rickets (including a 25-hydroxyvitamin D threshold of <25 nmol/L).
What was found
125 cases met the case definition, representing an annual incidence of 0.48 (95% CI 0.37 to 0.62) per 100,000 children under 16 years. 116 cases were in children under 5 years, an annual incidence of 1.39 (95% CI 1.05 to 1.81) per 100,000. Males accounted for 70% of cases compared to 30% females (OR 2.17, 95% CI 1.25 to 3.78). 43% of cases were Black and 38% were South Asian. 77.6% were not taking recommended vitamin D supplements. Complications included delayed gross motor development (26.4%), fractures (9.6%), hypocalcaemic seizures (8%), dilated cardiomyopathy (3%), and death (1.6%, n=2). Eight confirmed cases were excluded from the incidence estimate because 25-hydroxyvitamin D was not <25 nmol/L.
Why it matters
This provides the first national prospective incidence estimate of symptomatic nutritional rickets in UK secondary care. While incidence is low overall, severe preventable complications and deaths occur disproportionately in young Black and South Asian children with low vitamin D supplementation uptake.
Limits
The study captured only cases presenting to secondary care and relied on paediatrician notification, likely missing mild or primary-care managed cases. The rigid case definition excluded radiologically and biochemically confirmed rickets cases with 25-hydroxyvitamin D levels at or above 25 nmol/L. Dietary calcium intake was not directly quantified.
Cited by
- supports Severe vitamin D deficiency in infants can cause profound hypocalcemia resulting in afebrile convulsions.